Energy absorbers may aid in preventing injury and saving lives by providing cushioning, by extending the period of time over which the force of an impact may act on the body of a person and/or by diminishing the peak force that a person may be subjected to over that period of time. In one exemplary application, an energy absorber may be positioned in the instrument panel of a vehicle in an area likely to be impacted by the knees of either of the vehicle driver or front passenger. One such prior art energy absorber may comprise five separate metal pieces which may be attached to a back side of the instrument panel (i.e., they are not visible from inside the cabin of the vehicle) and also attached to a structural cross member that is rigidly mounted to the frame of the vehicle. Although such an energy absorber may be effective, the use of metal in its construction may be expensive and may add an unacceptable amount of weight to the vehicle. Further, assembling separate components to form a single energy absorber may be complex and may require an excessive amount of labor. It may therefore be desirable to provide a one-piece energy absorber made of a light weight material.
Additionally, vehicle occupants may be of different weights and sizes which may further complicate the management of energy during an impact. Providing an energy absorber capable of effectively cushioning a 220 lb., 6′ 5″ person may offer too much resistance to effectively cushion a 5′ 0″, 100 lb. person. Conversely, an energy absorber capable effectively cushioning the impact of the 5′ 0″, 100 lb. person may offer an insufficient level of resistance to effectively cushion the 6′ 5″, 220 lb. person during a collision. It would therefore be desirable to provide a single energy absorber that can effectively cushion persons of varying size and weight.